Homo sapiens was dark-skinned early on

New study on skin colors dispels old prejudices

Philadelphia / Vienna - The question of whether there are human "races" and how they should be classified has not only preoccupied anthropology for over 200 years. Even if the concept is now largely scientifically obsolete, today's representatives of Homo sapiens differ externally by their skin colors.

Was man originally dark-skinned?

Since modern humans originated in Africa and Africans living today have dark skin, it is generally assumed that the dark skin color was also the more original. But as a new study by researchers around Sarah Tishkoff (University of Philadelphia) in the journal "Science" shows, the matter is a lot more colorful and complicated than even human geneticists previously thought.

Because they too assumed that only a few genes are responsible for the color tones of our skin: in Africans, for example, the MC1R gene, which is responsible for dark pigmentation.

Many shades of "brown"

For their new study, Tishkoff and her team examined the skin of more than 2,000 people from Ethiopia and Tanzania (both East Africa) and South African Botswana, i.e. they determined their amazingly varied skin tones and took DNA samples from the test subjects who came from different ethnicities.

The way to them was sometimes anything but easy:

The results were somewhat surprising. The researchers found a total of eight areas of the genome that are related to pigmentation and explain around 30 percent of the variation. And for each of the eight areas there was a variant that ensures lighter and darker skin. Four of the lighter variants were created more than 270,000 years ago, i.e. before the first appearance of Homo sapiens, and four at all around 900,000 years ago.

The OCA2 gene, for example, which is associated with pigmentation in Europeans, has been around for more than 600,000 years. This in turn means that these variants existed before the division into modern humans, Denisovans and Neanderthals.

Lighter pigmentation came before darker

Three of the particularly dark skin variants of African ethnic groups may only have emerged as a variant of lighter preforms. And the oldest variants that have been discovered are responsible for light skin color. The fact that the representatives of the San in Botswana have a particularly light skin color, although they are considered to be one of the oldest populations of Homo sapiens, fits well into the picture.

The fair skin of chimpanzees

Tishkoff and her team also speculate how the darker pigmentation came about, pointing out that chimpanzees have light skin beneath their dark fur. Dark skin was only beneficial when our ancestors lost their body hair and emigrated from the forest to the steppe. (Klaus Taschwer, October 14, 2017)